1. Field of the Invention
The present invention generally relates to equipments and methods for displaying a specification of behavior of a real time system and, more particularly, to an equipment and method for displaying on a display screen the simulated behavior specification of a real time system, such as typically a communication system or an exchange system.
2. Description of the Related Art
A prior art method for expressing the behavior specification of a real time system such as typically a communication system or an exchange system and for displaying the simulated behavior specification on a display screen is reported, for example, in a Proceeding, Information Processing of Society, 39th Conference (October 1989), 5S-9, pp. 1582-1583, 1989 or in a Technical Report, Information Processing of Society of Japan, SE 71-1 pp. 1-8, 1990, 2. 8. In this prior art method, behavior objects (objects) corresponding to the constituent elements of the real time system necessary for explanation of the operation of the system are expressed in the form of structure icons (graphical symbols) and changes in the states of the objects when the operation of the system is changed with time are reflected in changes in the states of the structure icons displayed on the display screen.
According to the above prior art method, the behavior specifications of the respective elements of the real time system corresponding to service functions are previously defined as behavior scenarios of system behaviors arranged on a time series basis and the entire behavior specification of the system is expressed in the form of combinations of such behavior scenarios.
In each operational scenario, a first version of sequence of messages to be transferred between objects is prepared on the basis of changes in the states of the objects and then the first version of message sequence is modified to obtain an accurate message sequence.
In the prior art technique, since the behavior scenario is based not on user's operational sequence but on the message sequence to be transferred between the objects of the interior of the real time system, the system designer can relatively easily understand it. However, it is relatively hard for a user (system purchase customer) wanting to understand the function and operation of the real time system to understand it on the basis of the system behavior specification displayed on the display screen, because, for example, the user cannot interactively give a desired operational instruction to confirm a response operation from the system.
Accordingly, the prior art has had such a problem that the user cannot positively check the intended behavior specification on the display screen, and thus when the user instructs the system designer to modify it after the system design proceeds into its test stage or after-shipment stage with the system functions different in sense or image between the user and designer, this involves troublesome modification.